THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)	9 Months Ended
	Sep. 30, 2020 USD ($) segment $ / shares shares	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)
Class of Stock
Number of operating segments | segment	1
Cash received per share in transaction (USD per share) | $ / shares	$ 3.00
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Change in Accounting Principle, Accounting Standards Update, Transition Option Elected [Extensible List]	us-gaap:AccountingStandardsUpdate201604CumulativeEffectPeriodOfAdoptionMember
Stockholders' equity | $	$ (1,442,561,000)	$ (1,707,838,000)	$ 3,898,318,000	$ 3,805,761,000	$ 3,843,597,000	$ 3,551,801,000
Cumulative Effect, Period of Adoption, Adjustment
Class of Stock
Stockholders' equity | $			$ 0
New Match Common Stock
Class of Stock
Stock issued in transaction per parent company share (shares) | shares	1
Cash received per share in transaction (USD per share) | $ / shares	$ 3.00